Gay rights activists and their supporters in the chamber erupted in cheers and applause following the Senate vote.

Delaware's same-sex marriage bill was introduced in the Democrat-controlled legislature last month, barely a year after the state began recognizing same-sex civil unions. The bill won passage two weeks ago in the state House on a 23-18 vote.

While it doesn't give same-sex couples any more rights or benefits under Delaware law than those they have in civil unions, supporters argued same-sex couples deserve the dignity and respect of married couples.

They also noted that if the U.S. Supreme Court strikes down the Defense of Marriage Act, which bars married gay couples from receiving federal benefits, civil unions would not provide protections or tax benefits under federal law to same-sex couples in Delaware.

Opponents, including scores of conservative religious leaders from across the state, argued same-sex marriage redefines and destroys a centuries-old institution that is a building block of society.

Under the bill, no new civil unions will be performed in Delaware after July 1, and existing civil unions will be converted to marriages over the next year. The legislation also states that same-sex unions established in other states will be treated the same as marriages under Delaware law.

The bill does not force clerics to perform same-sex marriages that conflict with their religious beliefs. But under an existing Delaware law banning discrimination based on sexual orientation, business owners who refuse to provide marriage-related services to same-sex couples for reasons of conscience could be subject to discrimination claims.

Delaware, at tiny state on the U.S. Atlantic coast, joins neighboring Maryland and the nearby District of Columbia as jurisdictions that have approved gay marriage. Last week, Rhode Island became the 10th state to allow gay and lesbian couples to wed, with independent Gov. Lincoln Chafee signing the bill an hour after its final passage.